mmc: sunplus: fix return value check of mmc_add_host()

[PATCH] mmc: sunplus: fix return value check of mmc_add_host()

Posted by Wei Chen 2 years, 7 months ago

mmc_add_host() may return error, if we ignore its return value,
1. the memory allocated in mmc_alloc_host() will be leaked
2. null-ptr-deref will happen when calling mmc_remove_host()
in remove function spmmc_drv_remove() because deleting not
added device.

Fix this by checking the return value of mmc_add_host(). Moreover,
I fixed the error handling path of spmmc_drv_probe() to clean up.

Signed-off-by: Wei Chen <harperchen1110@gmail.com>
---
 drivers/mmc/host/sunplus-mmc.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/host/sunplus-mmc.c b/drivers/mmc/host/sunplus-mmc.c
index db5e0dcdfa7f..a96e90ea6541 100644
--- a/drivers/mmc/host/sunplus-mmc.c
+++ b/drivers/mmc/host/sunplus-mmc.c
@@ -902,7 +902,7 @@ static int spmmc_drv_probe(struct platform_device *pdev)
 
 	ret = mmc_of_parse(mmc);
 	if (ret)
-		goto probe_free_host;
+		goto clk_disable;
 
 	mmc->ops = &spmmc_ops;
 	mmc->f_min = SPMMC_MIN_CLK;
@@ -911,7 +911,7 @@ static int spmmc_drv_probe(struct platform_device *pdev)
 
 	ret = mmc_regulator_get_supply(mmc);
 	if (ret)
-		goto probe_free_host;
+		goto clk_disable;
 
 	if (!mmc->ocr_avail)
 		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
@@ -927,9 +927,17 @@ static int spmmc_drv_probe(struct platform_device *pdev)
 	host->tuning_info.enable_tuning = 1;
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
-	mmc_add_host(mmc);
+	ret = mmc_add_host(mmc);
+	if (ret)
+		goto pm_disable;
 
-	return ret;
+	return 0;
+
+pm_disable:
+	pm_runtime_disable(&pdev->dev);
+
+clk_disable:
+	clk_disable_unprepare(host->clk);
 
 probe_free_host:
 	if (mmc)
-- 
2.25.1

Re: [PATCH] mmc: sunplus: fix return value check of mmc_add_host()

Posted by Ulf Hansson 2 years, 6 months ago

On Thu, 22 Jun 2023 at 11:02, Wei Chen <harperchen1110@gmail.com> wrote:
>
> mmc_add_host() may return error, if we ignore its return value,
> 1. the memory allocated in mmc_alloc_host() will be leaked
> 2. null-ptr-deref will happen when calling mmc_remove_host()
> in remove function spmmc_drv_remove() because deleting not
> added device.
>
> Fix this by checking the return value of mmc_add_host(). Moreover,
> I fixed the error handling path of spmmc_drv_probe() to clean up.
>
> Signed-off-by: Wei Chen <harperchen1110@gmail.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/sunplus-mmc.c | 16 ++++++++++++----
>  1 file changed, 12 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/host/sunplus-mmc.c b/drivers/mmc/host/sunplus-mmc.c
> index db5e0dcdfa7f..a96e90ea6541 100644
> --- a/drivers/mmc/host/sunplus-mmc.c
> +++ b/drivers/mmc/host/sunplus-mmc.c
> @@ -902,7 +902,7 @@ static int spmmc_drv_probe(struct platform_device *pdev)
>
>         ret = mmc_of_parse(mmc);
>         if (ret)
> -               goto probe_free_host;
> +               goto clk_disable;
>
>         mmc->ops = &spmmc_ops;
>         mmc->f_min = SPMMC_MIN_CLK;
> @@ -911,7 +911,7 @@ static int spmmc_drv_probe(struct platform_device *pdev)
>
>         ret = mmc_regulator_get_supply(mmc);
>         if (ret)
> -               goto probe_free_host;
> +               goto clk_disable;
>
>         if (!mmc->ocr_avail)
>                 mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
> @@ -927,9 +927,17 @@ static int spmmc_drv_probe(struct platform_device *pdev)
>         host->tuning_info.enable_tuning = 1;
>         pm_runtime_set_active(&pdev->dev);
>         pm_runtime_enable(&pdev->dev);
> -       mmc_add_host(mmc);
> +       ret = mmc_add_host(mmc);
> +       if (ret)
> +               goto pm_disable;
>
> -       return ret;
> +       return 0;
> +
> +pm_disable:
> +       pm_runtime_disable(&pdev->dev);
> +
> +clk_disable:
> +       clk_disable_unprepare(host->clk);
>
>  probe_free_host:
>         if (mmc)
> --
> 2.25.1
>